Bake the cake according to instructions and refrigerate overnight.
Combine the cream and chocolate chips in a microwaveable bowl. Microwave in 30 second intervals, stirring in between in each one, until it is fully melted and smooth. Cool overnight in the refrigerator.
Crumble the cake into a large bowl, and mix with the frosting. Using a small cookie scoop, make small one inch balls. Make a dent in the ball, add 1 tsp of ganache, close the ball. Freeze the truffles for 20 minutes.
While the balls are freezing, melt the chocolate. Move the truffles from the freezer to the refrigerator. Taking out only a few truffles at a time, dip them in the melted chocolate, scoop them out with a fork, tap off the excess chocolate and transfer to wax paper. Top with sprinkles and allow the chocolate to set completely.